Intimate Partner Violence and Abuse: A Qualitative Exploration of UK Military Personnel and Civilian Partner Experiences

Purpose The prevalence of Intimate Partner Violence and Abuse (IPVA) perpetration and victimisation has been found to be higher in serving and ex-serving military samples compared to civilians. Despite this, there is a lack of qualitative research exploring the IPVA experiences of couples in which one or both partners are serving or have served in the military. This qualitative study aimed to explore IPVA experiences within the UK military community from the perspective of serving and ex-serving military personnel and civilian partners of UK military personnel. Method One-to-one telephone interviews were conducted with 40 serving and ex-serving military personnel (29 male, 11 female) and 25 female civilian partners. Data was analysed using thematic analysis. Results Four superordinate themes were derived: (1) patterns and directions of IPVA, (2) types of IPVA, (3) perceived drivers of IPVA and (4) perceived impact of IPVA. The findings point to frequent bidirectional abuse in part driven by poor communication and emotion regulation, whilst also highlighting the experiences of severe IPVA victimisation of civilian partners by military personnel motivated by power and control. Perceived drivers of both IPVA perpetration and victimisation include military factors borne of military culture or training, alcohol and mental health difficulties. Conclusion These results highlight the role of cultural norms, as well as the role of emotion dysregulation, poor communication skills and mental health difficulties in explaining and perpetuating abuse within ecological theoretical frameworks of violence among couples within which one or both partners are serving or ex-serving military personnel.

Intimate Partner Violence and Abuse (IPVA) includes emotional abuse (e.g. belittling, humiliating), psychological abuse (e.g. threatening behaviour, verbal aggression) and physical or sexual violence between current and former partners (WHO, 2012). The impact of IPVA can be severe and widespread, marking it is as a public health issue and global health priority (WHO, 2012). In addition to affecting the physical and mental health of victim-survivors (Campbell, 2002), IPVA can affect social and occupational functioning (Hines & Douglas, 2018;Johnson et al., 2014) and have a long-term negative impact on children who are witnesses to domestic abuse (Domoney & Trevillion, 2021;Jouriles & McDonald, 2015). There is a cost to society of IPVA, with an estimated £66 billion spent on victim-survivors of domestic abuse in England and Wales between March 2016 and March 2017 (Oliver et al., 2019).
Our understanding of IPVA typologies, patterns and drivers has advanced greatly in the past 25 years (Gibbs et al., 2020). The ecological framework for violence (WHO, 2002), which includes partner violence, views interpersonal violence as the outcome of the interaction among many factors across four levels-the individual, the relationship, the community, and the societal. In addition to general risk factors, such as socioeconomic status, childhood trauma, gender inequality, Gibbs and colleagues (2020) view involvement in armed conflict as a significant additional driver of IPVA in some communities due in part to increased risk factors at an individual level through exposure to traumatic events and the chronic stress of living under constant threat of attack resulting in worsened mental health and substance misuse (Gibbs et al., 2020). In addition, couples in which one or both partners are serving in the military can be exposed to unique stressors, including frequent geographical relocations and periods of separation, which may negatively impact relationships and increase risk of IPVA (Clark & Messer, 2006;McLeland et al., 2008;Rentz et al., 2006). Evidence suggests that stressed couples are more likely to be aggressive couples (Eckhardt & Parrot, 2017). Chronic external stresses interact with individuals' dispositional and regulatory deficiencies, and can result in a spill-over of these stresses into the relationship. Drawing on theories of social learning (Bandura, 1978), it has also been suggested that socialisation into military culture and attitudes, which include a defined hierarchy and the legitimisation of aggression within military contexts, can result in "occupational violence spill-over" into the family home (Bradley, 2007;Trevillion et al., 2015). There is evidence to suggest that both IPVA perpetration and victimisation is more prevalent among serving and ex-serving military personnel compared to the general population Rentz et al., 2006;Sparrow et al., 2020), even after adjusting for sociodemographic characteristics .
In-depth exploration of the types, patterns, impact of, and motivations for, IPVA behaviours perpetrated or experienced by serving and ex-serving military personnel or their partners is lacking, with no such research on UK military communities published to date. Although quantitative data (e.g. MacManus et al., 2022) allows for meaningful comparison of prevalence of IPVA within a military population with the general population and is instrumental in establishing potential risk factors, it is more difficult to explore the nuanced ways in which such factors might affect experiences of IPVA, what triggers may exist and how these may differ between military personnel and their civilian partners.
There remains a need to better understand the lived experiences of serving and ex-serving military personnel and their partners to understand how to best protect victim-survivors of IPVA and tailor interventions for those who engage in abusive behaviours. This is also essential to inform the responses by the Armed Forces, the UK Government, and relevant charities and state services. The current study aimed to qualitatively explore the IPVA experiences of serving and ex-serving UK military personnel and civilian partners to address these gaps. In particular, we wanted to understand the patterns, types and severity of abusive behaviours experienced within relationships and how these experiences affected the participants and their family. To allow us to describe and compare the range of experiences of IPVA perpetration and victimisation within couples in which one or both partners are serving or ex-serving military personnel, we utilised data from interviews with serving and ex-serving military personnel and civilian partners of serving or ex-serving military personnel who reported IPVA behaviours in their relationship(s).

Study Design
The research forms part of a wider mixed-methods research programme aiming to better understand the experiences and complexities of IPVA within the UK Armed Forces community and allowing for triangulation of findings (Alves-Costa et al., 2021Lane et al., 2022, under under review-a, under review-b;MacManus et al., 2022). Using a critical realist approach, this paper draws on qualitative data from two samples exploring the experiences and impact of IPVA in relationships in which one or both partners are serving or ex-serving military personnel. Samples were recruited in parallel and had comparable interview schedules (Study 1 and Study 2) and were combined for the purpose of this study in order to provide as comprehensive an account of IPVA in military communities as possible. The first sample (Study 1) included serving and ex-serving military personnel who had reported either perpetrating or experiencing abusive behaviours in the past 12 months and the second sample (Study 2) included civilian partners who had been in an abusive relationship with a serving or ex-serving member of the UK Armed Forces.

Definitions
IPVA is defined as "any behaviour within an intimate relationship that causes physical, psychological or sexual harm to those in the relationship" (WHO, 2012, p1). In this paper, the term 'bidirectional abuse' is used to describe cases where participants report relationships with mutual violence, whereby both partners engaged in abusive behaviour toward the other. This may be symmetrical or asymmetrical in terms of severity, but both partners are considered to instigate abusive behaviours and the behaviours are not suggestive of perpetration with retaliation or resistance. We use the term 'unidirectional' abuse in cases where participants report perpetrating IPVA towards their partner or being a victim-survivor with no reports of bidirectional violence. Unidirectional abuse may occur with or without instances of retaliation or resistance.
Given that this study focuses on relationships and relationship behaviours occurring during and after military service, the terms 'military personnel' and personnel will be used to refer to the experiences and perceptions of both serving (active duty) and ex-serving (veteran) personnel in presenting the findings. Differences between serving and exserving personnel are pulled out where relevant, although please note serving status is captured at time of interview therefore an ex-serving military respondent may speak of relationships which occurred whilst serving. In addition, recent quantitative research highlights no significant difference in reporting of IPVA perpetration or victimisation between serving and ex-serving UK military personnel, and many risk factors for IPVA perpetration and victimisation overlap  and are likely relevant both during and after leaving Service, such socialisation into military culture or trauma exposure on deployment (Lane et al., under review-b;MacManus et al., 2022). Participants who identify as civilian victim-survivors will be referred to throughout the findings as civilian respondents. Their serving or ex-serving military (ex)partners will be referred to as 'military partners'. The term participants will be used to describe the whole sample where relevant.

Recruitment
Military personnel were recruited from a sub-sample of respondents to Phase 3 of the King's Centre for Military Health (KCMHR) Health and Well-being Cohort Study (Stevelink et al., 2018). Within the self-completed survey, serving and ex-serving personnel reported on experiences of victimisation and perpetration of IPVA in the past year, including psychological, emotional, physical and sexual abuse . 266 serving or ex-serving military personnel (188 men and 78 women) who reported IPVA perpetration and/or victimisation, and consented to be followed up, were invited to take part.
Individuals who identified as civilian victim-survivors of IPVA occurring during relationships with military or exmilitary personnel were also eligible for inclusion. Civilian respondents were recruited via advertisements through national military and civilian welfare support charities, clinical services for serving military personnel and their families (including military base GPs and welfare services) or services for veterans and their families, and specific support organisations for victim-survivors of IPVA. Although civilian respondents were recruited based on their experiences of victimisation in a relationship with a military partner, all participants were asked about victimisation and perpetration of abuse or retaliation within relationships at interview.
Recruitment for both groups was open to all genders, ethnicities and sexual orientations. Prior to involvement, participants received study information and provided written consent. Semi-structured one-to-one telephone interviews lasting between one to two hours were conducted between January to August 2018. All interviews were audiotaped/ recorded and transcribed verbatim before anonymisation. Participants were given £25 as compensation for their time.

Analysis
Interviews were analysed using Reflexive Thematic Analysis (Braun & Clarke, 2020), a method well-suited to research questions regarding lived experiences. It allows for exploration of patterns of meaning across the data using both deductive themes informed by theory and literature, and inductive, data-driven themes. This analysis approach allows for immersion in the data through the inductive coding process, whilst acknowledging the lens provided by existing frameworks and theory. In this study, WHO definitions of IPVA, ecological frameworks of violence, and occupation violence spill-over theories were used as scaffolding for data-driven themes. Following the transcription and familiarisation with the data, an initial coding framework was constructed through a process of open coding (Braun & Clarke, 2020). This initial framework was applied to the remaining transcripts, generating initial themes and subthemes. Coding was conducted by two authors (RL, RG). The first coder (RG) coding 50% of the data, which was reviewed by the second coder (RL), who then adapted and added to the early to the sensitive nature of the interviews, a risk management plan was developed. All participants were offered the opportunity to discuss any concerns following their interview with an independent clinician and were signposted to support services.

Participants
The sample (n = 65) included serving and ex-serving military personnel (n = 40) and civilians in current or prior relationships with serving or ex-serving military personnel (n = 25). Demographics and military characteristics of military personnel are presented in Table 1. The majority of military respondents described themselves as White or White British. Most personnel were male; between 35 and 50 years of age; reported relationships with civilian partners; were in the Army; were ex-serving at time of interview; were/ or had been Regular military personnel; were Non-Commissioned Officers (NCOs); and had previously deployed. Two participants described their experiences within samesex relationships. Most military personnel spoke of multiple relationships with a range of patterns, severity and types of IPVA across their lifetime.
Demographics of civilian respondents and military characteristics of their military partners are presented in Table 2. All civilian respondents in the study were women in heterosexual relationships. The majority of civilian respondents described themselves as White British and were between 35 and 49 years of age. At the time of interview, all but one civilian respondent were no longer in an abusive relationship with a currently serving or ex-serving member of the Armed Forces. Most military partners of civilian respondents were in the Army, were ex-serving, and were NCOs. All had previously deployed and served as Regular personnel, though some served with the Reserves before or after their Regular service. Some participants reported the military characteristics of partners at the time of interview; for others, this reflected their partners' military characteristics during the relationship or at the point of leaving Service. In addition, some military partners served across branches. Differences according to personnel military characteristics such as Service and rank were explored within the data, however due to these complexities meaningful comparisons were restricted.
While many military personnel were ex-serving at time of interview and many military partners of civilian respondents were reported to be ex-serving, participants spoke of relationships which spanned the military person's career in the UK Armed Forces (i.e. before, during and after military service). theme development using the remaining data. The coding frame was reviewed and refined through progressive iterations and discussions within the research team, and themes and subthemes were defined. All themes were data-driven, and range from descriptive to more latent themes suited to answer the research questions posed. Given the descriptive and potentially identifying nature of the themes and subthemes, we have opted not to present quotes to protect participant confidentiality in some areas. Comparisons across sub-groups (e.g., gender, reported IPVA experiences, branch of Service, serving status, rank, military/civilian) were considered and reported when observed. Data analysis and management was supported by QSR Nvivo software (QSR International Pty Ltd., 2020).

Patient and Public Involvement (PPI)
The research programme benefitted from consultation and feedback from experts by experience and by training. A PPI group was developed involving consultation with professionals (military researchers, IPVA researchers and services, mental health researchers and services, members of the UK Armed Forces) and civilians with personal experience of abuse by serving or ex-serving military partners. Feedback from this group helped inform the interview protocols and refine the frameworks, decreasing the possibility for researcher bias. PPI events were also organised to gain feedback on the findings, which allowed the results to be verified and validated.

Reflexivity Statement
It is important to reflect that all authors of this paper are White European, female, have never served in any Armed Forces, and have undertaken postgraduate study. Authors have no current or previous affiliations to the UK Ministry of Defence or military. It is possible that author characteristics and pre-conceptions of the military and/or of IPVA have affected the way the interviews were conducted and the analysis was approached, and influenced participant responses. However, the non-military serving status of interviewers was also considered likely to reduce barriers to disclosing issues with the military institution.

Ethics
Ethical Committee approval for interviews with serving/exserving personnel was obtained from the UK Ministry of Defence Research Ethics Committee (823/MODREC/17). Ethical Committee approval for interviews with civilian partners was granted by the King's College London Research Ethics Subcommittee . Due how the abuse progressed over time. Theme 2 describes the types of abuse reported, covering participant accounts of emotional and psychological abuse, controlling behaviours, physical abuse and sexual abuse. Theme 3 presents the perceived drivers of abuse, including motivations and triggers identified in participant narratives. Theme 4 explores participants' perceptions of the impact of abuse on their or their partner's physical or mental health, their parenting and on their children, and on their occupational and social functioning.

Findings
Four primary themes were derived from the data which describe experiences of IPVA among serving and ex-serving military personnel and civilian respondents (see Table 3). Theme 1 describes the patterns of abuse experienced by participants, exploring the direction and severity of abuse within their relationships, how they resolved conflict and  2 Not known 3 Deployment experience** Deployed 27 Not deployed 0 Note: Two civilian respondents reported more than one abusive relationship with a serving or ex-serving military partner, with the total sample reporting on 27 abusive relationships with military personnel. *These groups aren't mutually exclusive. Some military partners were reported to serve in multiple Service branches and as both regular and reservist military personnel. **Deployment experience does not include detail on whether military personnel held combat roles on deployment, although civilian respondent narratives would suggest this was common. end of their relationship. A minority described the abuse to be present from the early days of their relationship and to remain stable over the course of their relationship. Some reported that behaviours within their relationships improved over time, for instance as they got older, left Service and spent more time together, or learnt better conflict resolution skills.
[ Similarly, most civilian respondents described a pattern of escalating abuse perpetrated by their military partner, with less frequent and less severe forms of psychological and emotional abuse and controlling behaviours in the beginning of the relationship which escalated in frequency, intensity and severity (see Theme 3, Subtheme 2 'Triggers' for further examples).
In the beginning [(ex)partner exerting control] was only every now and again, and then it would be the odd text message. But, as it got to the last year, year-and-ahalf of the relationship, it was incessant; it didn't stop. (P7; Civilian partner of military personnel) Most civilian respondents described the relationship to end in a context of heightened abuse, often physical. While for some civilian respondents, the onset of the abuse was easily identified, for others there was a sense that the slow escalation made recognition of the gravity of the abuse difficult. In contrast to military personnel, some civilian respondents also described ongoing abuse post-separation, as depicted in the example below.
[During the divorce process], my ex-husband kept ringing me, kept turning up at my parents' house. He would ring me or message me and say that he was going to wait outside of where I was working at the

Theme 1: Patterns of Abuse
Direction of abuse and mutuality. Most military personnel reported having experienced relationships in which bidirectional abuse occurred between partners; this was particularly prominent among dual military couples. Most also reported experiences of unilateral IPVA victimisation in one or more relationships and a large minority reported unilateral perpetration of abusive behaviours (see Table 1). All military personnel who reported perpetration of abuse had previously deployed. No gender or other group differences (such as by Service Branch, rank or engagement or serving status) in the experiences of IPVA were noted. Civilian respondents all described being the victim-survivor of unidirectional abuse perpetrated by their military partner. Only a minority reported retaliation, mostly verbal aggression, in response to the abuse experienced, but such behaviour was not considered commensurate with bidirectional abuse.
Severity. While civilian respondents all described frequent moderate to severe experiences of unilateral IPVA victimisation perpetrated by their military partners, the majority of military personnel reported less severe IPVA experiences (such as verbal aggression, lower level controlling behaviours and emotional abuse). Some military personnel appeared to minimise the abuse within their relationships or were more reluctant to disclose details in interviews compared with civilian respondents. However, some military personnel did report experiencing or perpetrating frequent or severe abuse. Reports of more severe experiences of unilateral victimisation or bidirectional abuse were made by both male and female military personnel. Severe reports of IPVA perpetration were more prominent among male personnel.
Progression over time. Many military personnel described how the abusive behaviours within their relationships increased over time and were more severe towards the Physical abuse. Some military personnel described being exposed to multiple types of abuse (i.e. physical, and emotional/psychological/controlling), although this was more common in the narratives of civilian partners. Among military personnel, physical violence often escalated from verbal aggression. Both male and female personnel reported perpetrating physical violence (e.g. hitting, slapping, pushing), often towards objects but also towards their partner. More severe forms of physical violence perpetration (e.g. punching) were more prominent in reports by male personnel. Sexual abuse was more prominent among the narratives of civilian respondents, although again represented a minority. Among civilian respondents who did describe sexual violence, this was increasingly common towards the end of the relationship as violence within the relationship generally escalated. Such behaviours often occurred within the context of wider controlling behaviours and emotional abuse.

Theme 3: Perceived Drivers of Abuse
Motivations. Within some military personnel narratives, the motivations behind the abuse they either perpetrated or experienced were perceived to stem from the need to assert power or control. More frequent IPVA was reported in those relationships. In some cases, the apparent need for power or control by both male and female personnel was perceived to be related to military culture and socialisation, such as the need for order and the expectation of subordination, as illustrated in the quote below. Among civilian respondent narratives, the majority described the IPVA they experienced to be more clearly motivated by their military partner's need to assert power or control. Civilian respondents also perceived the psychological and physical injuries sustained as a result of IPVA perpetrated by their military partners to impair their ability to parent and protect their children. Civilian respondents reported impaired functioning across a number of parenting domains, such as increased levels of parenting stress, which impacted on the quality of parent-child relationships. Emotional neglect, overt hostility and controlling behaviours towards their children by their partners, mirroring the IPVA within their intimate relationship, were also reported.
My mental health had a huge impact on my children because their mother was constantly depressed.
[…] I look back to their childhood and I have lots of regrets where they were neglected, they weren't played with, they were shouted at, they were physically abused.

(P23; Civilian partner of military personnel)
Occupational and social functioning. A minority of military personnel reported impacts on their occupational or social functioning, including direct impact on their work and feeling isolated, as illustrated below. A few female personnel described their experiences of IPVA victimisation to impact on their social functioning secondary to the impact on their mental health and self-esteem, affecting how they relate to and perceive others.
We had a big argument. I didn't go into work the next day because it really affected me. Impacts on occupational and social functioning were more apparent among civilian respondents, who described difficulties finding or maintaining employment or cultivating Military personnel who reported more severe experiences of IPVA victimisation described a greater impact on their mental health. The latter mirrored narratives of civilian respondents, who described acute and chronic mental health difficulties stemming from the abuse they experienced and their continual state of fear and submission. These included but were not limited to, mental difficulties and disorders such as Post Traumatic Stress Disorder (PTSD), anxiety, low mood, difficulties with trust and poor self-esteem.
As the abuse escalated and spiralled, I became more scared of him and tried to just not lose my temper and just hide from him or stop him from blowing up to start off with. (P19; Civilian partner of military personnel) I had extreme anxiety, I had treatment for CPTSD -Complex PTSD myself, because of all the years of abuse.
[…] I was numb. I didn't get angry, I didn't get sad, I didn't really get happy. I just dissociated myself, and I was just like this empty shell of a thing. (P12; Civilian partner of military personnel) Impact on parenting and children. While some military personnel noted that their children would witness their relationship conflict, only a minority shared that their children were affected by the IPVA in their relationships. For example, some children were described to have developed difficulties relating to mental health or anger management. Some military personnel recognised that their controlling behaviour and high expectations also extended to their children. In contrast, all civilian respondents with children noted how their children were witnesses to violence within the household, with a few noting their military partners were aggressive towards their children. The reported consequences for children of civilian respondents were primarily the development of psychological difficulties, such as low mood and anxiety or PTSD symptoms, but also included increased aggression and school-related difficulties.
What he did do was then he would hit the children or grab the children by the throat or hair. He was al., 2016). A minority of serving or ex-serving military personnel reported unilateral perpetration of abuse. Minimal gender differences in IPVA experiences among serving and ex-serving military personnel were observed in patterns and types of IPVA, though reports of severe IPVA perpetration were more prominent among male serving or ex-serving personnel. This broadly supports our quantitative findings, that male serving or ex-serving personnel were significantly more likely to report perpetration of emotional, psychological and controlling abusive behaviours than their females counterparts . Civilian respondents were recruited as victim-survivors of abuse perpetrated by a military (ex)partner and all described experiences of moderate to severe unilateral victimisation, mostly motivated by the need for their serving or ex-serving military partner to assert power and control, and some which would have been appropriately labelled Intimate Terrorism (Johnson et al., 2014). Although these findings do not capture IPVA perpetration by civilian partners of military personnel (Park et al., 2021), they resonate with civilian partner experiences of IPVA perpetrated by military personnel found in other studies (Gray, 2016;Williamson, 2012) and supplement the military personnel narratives which appeared prone to under-disclosure of perpetration. Various motivations for perpetrating IPVA have been identified in the literature, including power/control, communication difficulties and jealousy (Johnson, 2006;Langhinrichsen-Rohling et al., 2012a). Although a minority of serving or ex-serving military personnel described experiences of perpetration or victimisation motivated by power or control, for many the abuse followed patterns of situational couples violence seemingly fuelled by negative intrapersonal factors (e.g. anger, mental health difficulties), interpersonal factors (e.g. relationship dissatisfaction) and difficulties with communication (Johnson, 2006;Langhinrichsen-Rohling et al., 2012a). These motivations align with the prevalent reporting of psychological abuse, especially verbal aggression, among military personnel. The findings demonstrate the significance of emotion dysregulation and poor communication skills in IPVA experiences, showing some support for the frustration-aggression hypothesis, whereby increased emotional arousal, particularly anger, may explain the association between work-family conflict or marital discord and IPVA (Park et al., 2021). In addition, poor conflict resolution was described in both serving and ex-serving military personnel and civilian respondent narratives, at times perpetuating the abuse, highlighting distinct areas for interventions to target. Poor conflict resolution was especially prominent in relationships in which bidirectional abuse took place, suggestive of mutually dysphoric or retaliatory violence (Langhinrichsen-Rohling, 2010

Discussion
This research used qualitative data to explore the IPVA experiences of serving and ex-serving UK military personnel as well as civilian partners of serving or ex-serving military personnel: data on IPVA experiences of UK serving and ex-serving military personnel, recruited from a sample who had previously endorsed IPVA perpetration or victimisation in a self-administered survey Stevelink et al., 2018), and data from civilian victimsurvivors of an abusive relationship with a military person. Four main themes were identified, describing the patterns of IPVA perpetrated or experienced by participants, the types perpetrated or experienced, the perceived drivers of IPVA and the perceived impact of IPVA.
Most serving and ex-serving military personnel in the sample reported bidirectional abuse or unilateral IPVA victimisation within a relationship. The high levels of bidirectional abuse resonates with findings from quantitative data in both civilian and military samples (Langhinrichsen-Rohling et al., 2012b;MacManus et al., 2022;Park et al., 2021). This highlights the importance of recognising the potential role of both partners in violent relationships, though the greater impact and likelihood of injury among females resulting from male violence perpetration, and the potentially different mechanisms for men and women in pathways to victimisation and perpetration is acknowledged (Archer, 2002). Bidirectional abuse was especially prominent in those reporting dual military relationships, a group currently under-represented in the military literature. The impact of such 'toxic relationships', in which bidirectional abuse occurs, on the individual partners as well as others in the household, especially children, is not sufficiently recognised (Domoney & Trevillion, 2021;Zemp et to local lockdown rules and social distancing, travel limitations and other stressors such as financial instability. Participants described a range of negative consequences of IPVA within their relationships, corroborating existing research findings in both civilian and the Armed Forces communities. These included effects on their physical and mental health (Campbell, 2002), their ability to parent and children's wellbeing (Christie et al., 2019;Jouriles & McDonald, 2015), and their ability to gain and maintain employment and relationships (Hines & Douglas, 2018;Johnson et al., 2014). Negative impact was reportedly greater and long-lasting within civilian respondent accounts. While the abuse experienced by serving or exserving military personnel compared to civilian respondents may have overall been reported as less severe and to have had a less significant impact, there may also have been a tendency for military personnel to minimise relationship difficulties and abuse. Less reporting of perpetration and the lack of clear examples of abusive behaviours perpetrated by military respondents, as well as the discrepancies in military respondent reporting identified between the KCMHR survey and within the interviews, may be driven by tendency for non-disclosure of perpetration and social desirability bias, as observed in civilian literature (Caetano et al., 2002). This may also be the case for those reporting victimisation, illustrated by the tendency for military personnel to minimise physical IPVA perpetrated by female partners. Indeed, military culture has been argued to encourage stoicism through machismo and promote legitimisation of violence within military contexts (Bradley, 2007;Trevillion et al., 2015), which could spill over into family spheres and may impact on insight and disclosure. These factors may also have impacted personnel awareness and insight of IPVA, and affected the reporting of drivers for abuse and impact, which were clearer and more prominent in the narratives of civilian respondents.
Methodological differences, especially in recruitment, may account for the differences between the accounts of serving and ex-serving military personnel and civilian respondents. As civilian partners were largely recruited from support services, it is likely they have experienced more severe forms of IPVA given the greater propensity to seek help from services for IPVA (Coker et al., 2000;Goodman et al., 2003) and may be better able to reflect on and articulate their experiences. It remains likely that serving and ex-serving military personnel who engage in or have experienced more severe IPVA motivated by power or control may be less inclined to participate than personnel with less severe experiences. Nevertheless, the purpose of this research was not to compare but to use the samples to complement one another and provide a fuller understanding of experiences of IPVA within couples in which one or both In line with research among civilian samples (Bell & Orcutt, 2009;Oram et al., 2013), individual level risk factors such as poor emotion regulation, mental health difficulties and alcohol use were described by participants as significant drivers of IPVA perpetration. Some participants described how military socialisation and the culture of high expectations of order and a need for control permeated their homes and were perceived to provide significant context for abuse perpetration, as frequently outlined in the literature (Bradley, 2007;Trevillion et al., 2015). This supports theories of top-down cultural and institutional influences on violence and aggression, as outlined in the Ecological Framework of violence (WHO, 2002), in which the role of society or societal institutions in impacting systems, attitudes, and beliefs at community, interpersonal and individual levels to influence whether violence is encouraged or inhibited is acknowledged. The prevailing military cultural norms described by participants, such as those around male dominance and hierarchy and the endorsement of violence as an acceptable method to resolve conflicts, are potent examples of how effective partner violence prevention strategies must consider more than individual risk factors.
Serving and ex-serving military personnel, and especially civilian respondents, identified high risk periods for IPVA, including the peri-deployment period and transitions out of Service. Post-deployment mental health was identified as a trigger for perpetration by both perpetrators and victim-survivors within the sample, corroborating research which has found deployment-related trauma to be associated with IPVA perpetration (Kwan et al., 2018Lane et al., 2022;MacManus et al., 2022). Poor mental health in the period following deployment was an especially prominent trigger for IPVA victimisation identified by male personnel, supporting previous quantitative research findings (Sparrow et al., 2017. The complex role of mental health difficulties in creating a context in which both perpetration and victimisation of abuse is more likely to occur warrants further exploration. Our findings suggest that internalising behaviours related to mental health difficulties (e.g. withdrawal) may increase vulnerability to abuse, whilst externalising behaviours (e.g. losing temper) may be more closely related to, and perhaps drive, IPVA perpetration. Civilian respondents identified isolation from peers following military related relocations as increasing their dependency on their military partner and, hence, vulnerability to abuse. This echoes previous research (e.g. Kern 2017) and is notable in understanding how military factors influence experiences of abuse among non-or ex-military partners and subsequent help-seeking. It is possible that factors relating to poor mental health and isolation are of particular significance in the context of the COVID-19 pandemic due problems and both perpetration and victimisation (e.g. Kwan et al., 2020;MacManus et al., 2022;Sparrow et al., 2020), the current results highlight the complex relationship between IPVA and mental health problems which requires better understanding and more nuanced public discourse. Improved awareness and identification of mental health problems within serving and ex-serving military personnel samples may help mitigate against abuse.
This research explored IPVA experiences from the perspectives of serving and ex-serving military personnel who reported IPVA perpetration or victimisation and civilian victim-survivors of abusive relationships with serving or ex-serving military personnel. Although these findings highlight the severe nature of abuse experienced by civilian partners of serving or ex-serving military personnel, characteristic of intimate terrorism, many military personnel respondents described bidirectional IPVA, often arising from situational couples violence, and which was often normalised or not identified as abuse. The results suggest that military culture and context play an important role in the occurrence of IPVA in couples in which one or both partners are serving or ex-serving military personnel, which warrants further exploration. Our findings also highlight the need to consider limitations of the often gendered victim/perpetrator binaries common in interventions and services, and the role of emotion dysregulation, poor communication skills and mental health difficulties in explaining and perpetuating abuse.

Conflict of Interest
The authors declare that they have no conflict of interest.
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons. org/licenses/by/4.0/. partners are serving or ex-serving military personnel. Unfortunately, subgroup analysis (for example by rank, serving status, and engagement status) was limited across datasets due the complexity of the IPVA and military characteristics data, for example many military personnel respondents reported different relationships with differing IPVA patterns. Further qualitative investigation is warranted to explore differences in experiences across groups. In addition, the present research recruited a predominantly White British sample and only a limited number of female serving or ex-serving military personnel. We were also limited in our observations of gender and sexual orientation given only two military personnel respondents reported same-sex relationships and civilian respondents were all female in heterosexual relationships. More research is required to explore experiences of dual military couples, LGBT couples, civilian partners of other genders and those from ethnic minority backgrounds in more depth.
There is currently a tendency for IPVA interventions to consider perpetrators and victim-survivors separately (Bates, 2016). While we recognise the appropriateness of such an approach in some cases, our findings of frequent bidirectional abuse within military and veteran relationships demonstrate that the reliance on a rigid victim/perpetrator binary is limited for some, stressing the need for programmes to acknowledge the bidirectionality of abuse in some relationships and also the need to work with couples. We acknowledge that this can present issues for risk management (e.g. Kohn 2010;Simpson et al., 2008), but a growing body of evidence now suggests that working with both partners can be very effective (Taft et al., 2016), e.g. when motivations for help occur within the context of parenting (Domoney & Trevillion, 2021). Furthermore, our findings highlight a need for perpetrator programmes to be tailored to female as well as male partners. Although some victim-survivor support services do cater for men, our findings highlight the need for more support services for male victim-survivors and services that have a specialist understanding of the military context. The present findings suggest a lack of understanding of how abuse may present, particularly non-physical forms of IPVA, stressing a need for training and awareness among personnel to support the identification of abuse within relationships where one or both partners are serving or have serviced in the Armed Forces. In addition to being a trigger for perpetration, personnel mental health and alcohol use was perceived to be an important trigger for IPVA victimisation within our sample, especially among male personnel who deployed, and the rich narratives shed light on the nuanced mechanisms underlying these risk factors. Considering the often unidimensional findings from quantitative research in this area, which have highlighted associations between mental health